100 THE DOMESTIC FOWL. 



an after stage of its progress, but consists wholly of 

 yolk, on whose surface the germ of the future chick 

 lies ; both ,the yolk and the germ being wrapped 

 round with a very thin membrane. 



EGG CLUSTER, OR OVARIUM. 



When the rudimental egg, still attached to the ova- 

 rium, becomes larger and larger, and arrives at a cer- 

 tain size, either its own weight, or some other efficient 

 cause, detaches it from the cluster, and makes it fall 

 into a sort of funnel, leading to a pipe which anato- 

 mists term the oviduct. 



Here the yolk of the rudimental egg, hitherto im- 

 perfectly formed, puts on its mature appearance of a 

 thick yellow fluid, while the rudimental chick or em- 

 bryo, lying on the surface, at the point opposite 

 that by which it had been attached to the ovarium, is 

 white, and somewhat paste like. 



The white, or albumen, of the egg now becomes 

 diffused around the yolk, being secreted from the 

 blood vessels of the egg pipe, or oviduct, in the form of 

 a thin, glairy fluid ; and it is prevented from mixing 

 with the yolk and the embryo chick, by the thin 

 membrane which surrounded them before they were 

 detached from the egg cluster, while it is strength- 

 ened by a second and stronger membrane, formed 

 around the first, immediately after falling into the 



